NOS tubes for Aesthetix Calypso

I recently purchased an Aesthetix Calypso. I really like the preamp, however I would like to purchase some NOS tubes for the unit. First priority would be a liquid smooth midrange, second would be soundstaging, third would be frequency extension. I would really appreciate some Calypso owners offering up some experience and suggestions with the NOS tubes. I would also like advice on where to purchase NOS tubes. My system consists of Maggie 3.6r's, 2 Vandersteen 2WQ subs, A SMC modded McCormack DNA-2, Resolution Audio Opus21 cdp, and all Purist Audio cabling. Thank you in advance for all your help.

You want Mullards. When I owned the Calypso I found them to be very smooth.
I have the same preamp. I’m very pleased with it. I’m also looking for tube replacements for both the 6922 and the 12ax7. I heard that Mullard 10M and Telefunken are fantastic tubes. I wonder where to buy these tubes.
Mullard 10's will cost you a fortune. Read the threads by Perfectionist. He recommends a few since he did a great deal of tube rolling. Also the great Jadem6 wrote a fabulous review and also identified so good tube to use with this pre-amp.
I just got mine and have Siemens 6922's and Dynaco 12ax7's. However, I expect to do some tube rolling. Why? Because I still have my Audio research LS 25 MKl and this per-amp is giving this new Calypso a real RUN FOR THE MONEY!!!!
Rick (RWD)
I have replaced the standard 6922 Reflector tubes with a Russian Reflector 6H23P-EB, witch results in greater dynamics and “swing”, But a bit more edgy style… USD 22.5 at Parts connexion.

I have also replaced the standard 12ax7 with a new production of Tungsol ECC803S Gold Pin, witch results in deeper soundstage. USD 29.95 at Parts connexion.

I am still seeking for a more lucid and full born sound.
I am currently using the Calypso. I have done some tube swapping, and have currently settled on the Mullard 10M 12ax7 gold pin and the Amperex 6922 PQ white label. I have found this combination very musical, although I admit to being influenced by all of the 'tube lore' floating around out there. Unfortunatly, these tubes are hard to come by. I was using the Mullard M8137 (for the 12ax7 slot) prior to the 10M, and I must say it was also excellent. Those are easier to come by, and much less expensive. I haven't AB'd them in a while, but I don't believe there is a huge difference. Also, long plate Mullards should be good.

Of course, it is a matter of personal taste, system synergy, and the quality of the actual tubes that will ultimately tell which is best for your system.

I had an opportunity to try several different nos brands, and ultimately decided to go with Ediswan 6922's and Telefunken 12AX7's. The Ediswan's are really smooth, yet detailed, and presented somewhat of a sweeter signature in the upper and middle registers. The bass was also very good and tuneful. The Eddies coupled with the Telefunken proved to be a great combo in the Calypso. Thank you for all your help.
Have had serious problems to mount on valves NOS Siemens (1960), the machine goes in protection or if it started emits a strong noise of current from the loudspeakers. As soon as return to normal Tesla or Sovtek, all it returns normal. You have ideas?
Have the tubes checked out and/or get a refund.
What's the average burn rate (i.e. how many hours can the tubes last ) for the Calypso?